This project proposes to develop an electrical stimulation augmented exercise device for individuals with incomplete spinal cord injury (iSCI). The device will provide a closed-chain, load bearing lower extremity exercise that has the potential to increase muscle mass, strength, and endurance, and may additionally reverse or slow the rate of loss of bone mineral density. The user will be encouraged to voluntarily perform the exercise, which will be augmented with electrical stimulation to complete the prescribed exercise range of motion. The stimulation controller will continuously adjust the stimulation profile to provide only the stimulation that is necessary to complete the exercise while encouraging the user to contribute their best volitional effort on each exercise cycle. We hypothesize that this exercise may provide motor retraining benefits to some users in addition to exercising lower extremity muscles and bones. In Phase I, we propose: 1) to modify our existing adaptive stimulation controller for use by individuals with iSCI who have the ability to voluntarily active the stimulated muscles, 2) to develop a simple visual feedback display to facilitate coordination between the user and stimulation controller, 3) to validate the display paradigm in a study with subjects without neuromotor deficits, and 4) to demonstrate feasibility of our approach by testing the device in a study with subjects with iSCI. In Phase II, we will further develop the adaptive stimulation controller, develop simple, user-friendly visual feedback paradigms to improve user/stimulation coordination, and demonstrate efficacy of the approach in a long-term study where individuals with incomplete SCI use the device in a motor retraining setting. The target market for the device is clinics who serve individuals with neuromotor disabilities such as incomplete SCI, traumatic brain injury, or stroke. The device will be competitively priced within the electrical stimulation-based exercise equipment market. [unreadable] RELEVANCE TO PUBLIC HEALTH: This project in relevant to public health because it may lead to development of a practical exercise device for individuals with iSCI that may prolong the onset of osteoporosis in the long bones of the legs and may lead to improved voluntary control of paralyzed lower extremity muscles when used as one component of a comprehensive post-SCI rehabilitation program. [unreadable] [unreadable]